GOP bill would repeal ObamaCare's exchanges if they're late

"My legislation will ensure that patients are not overburdened and that the administration will keep their commitment to the American people, or we get back to work on a better solution," Roberts said in a statement.

The exchanges are the centerpiece of healthcare reform, offering a venue for the uninsured to purchase coverage using subsidies from the government.

Enrollment is scheduled to begin on Oct. 1, with coverage starting Jan. 1 of next year.

Federal health officials say they are on target, and blame Republican opposition to ObamaCare for any delays.

Roberts's bill is co-sponsored by Sens. James Inhofe (R-Okla.), John Barrasso (R-Wyo.) and Thad Cochran (R-Miss.).